Ok guys, i know that each car requires a specific load rating for each tyre to withstand the weight but my question is, if i went a load rating under (e.g wanna pop some cheap steelies on for a little bit)

will the tyres pop under extreme force (eg. fanging the car around the block and corners or higher speeds e.g 110kph-->) or even at lower speeds and normal driving

or is it more a danger in the fact that the actual rim might buckle?

i'd be more concerned about the sidewall not being rigid enough due to structural differences, and flexing too much during hard cornering giving rise to the possibilty of the lip of the tyre popping off the rim

not to mention that the cars handling will feel very sloppy and lagging due to the lack of reponse because of the lack of rigidity in the tyres.

I know the corolla sportivos come with 16" as stock but i was curious to putting say 15' levin rims on just to see if the car feels lighter and goes any harder.

the tyres will not pop.. when the manufacturer make their tyres they test the load rating of a tyre BEYOND what its capable of so for example a 87 load rating tyre could have a true load rating of 95 - 96? well it is kinda common sense that you dont make something that will POP or DIE on the limit they specified... just take lifts for an example

That's called a Safety Factor, or Design Factor. It's rare that you'll see something with a factor less than 2 (ie is capable of taking twice the load that is expected before failing), and in some fields you get safety factors upwards of 5-10 (ie things are 5 times stronger than they need to be).

But the problem is legality. Whilst it most likely won't fail, it is still illegal to have tyres/wheels with a lower load rating than what came standard for the car, because it won't meet the safety factor specified in ADRs or the like.

the stock levin tyres are higher rated than the stivo tyres.

levin tyres are 195/60 R15 88V ..... the speedo wont be too far out either in fact only 1 km/h off so when ur speedo says 100 ur actually doin 99

seconding hiro's note about legality ill also add insurance ...... if they catch on that ur running under rated tyres ur car is not road legal and thus not insured either ......

i wonder if ur in an incident with someone n u take pics 2 prove they have under rated tyres, thus making their car illegal 2 b on the road thus making them @ fault ......much like a suspended driver even if its not their fault in the accident they still cop the blame ...... would it work much the same with the tyre incident i wonder

I smell a conspiracy looming ......

Ok so that seems understandble. You see i was curious if the actual rim also has a load rating which could be exceeded, so in other words i can go as small a rim and i want (and can fit) as long as the load rating of the tyre/rubber is acceptable?

I was going to pass on my stivo rims to my mate in his ascent, then we realised stivo's are 87, and ascent are 88, so it's now a no go.. gutted.

whitestivo

Did you want to pass them on to me ......of course theres money involved as well